Table 2:
Bias, precision and accuracy of eGFR for the CKD-EPI09-NB and CKD-EPI21 equations across cohorts.
| CKD-EPI09-NB | CKD-EPI21 | ||
|---|---|---|---|
| Total cohort (N = 4688) | Absolute bias, mL/min/1.73 m2, median (Q1–Q3) | −4.4 (−17.1 to 8.0) | −0.2 (−13.2 to 12.1) |
| Absolute bias, mL/min/1.73 m2, mean (95% CI) | −4.7 (−5.3 to −4.1) | −0.6 (−1.2 to 0.0) | |
| Precision, mL/min/1.73 m2 | 25.1 | 25.3 | |
| Relative bias, %, median (Q1–Q3) | −5.6 (−18.8 to 11.7) | −0.3 (−14.3 to 17.9) | |
| Relative bias, %, mean (95% CI) | 1.9 (0.5–3.3) | 7.6 (6.1–9.1) | |
| Accuracy, % (95% CI) | 70.3 (69.0–71.6) | 72.4 (71.1–73.6) | |
| Cancer cohort (N = 3313) | Absolute bias, mL/min/1.73m2, median (Q1–Q3) | −4.1 (−16.8 to 8.8) | 0.5 (−12.6 to 13.1) |
| Absolute bias, mL/min/1.73 m2, mean (95% CI) | −4.3 (−5.0 to −3.6) | 0.0 (−0.7 to 0.7) | |
| Precision, mL/min/1.73 m2 | 25.6 | 25.7 | |
| Relative bias, %, median (Q1–Q3) | −4.8 (−17.6 to 12.2) | 0.6 (−13.1 to 18.5) | |
| Relative bias, %, mean (95% CI) | 2.6 (0.9–4.3) | 8.4 (6.6–10.3) | |
| Accuracy, % (95% CI) | 72.0 (70.4–73.5) | 73.4 (71.9–74.9) | |
| Kidney donor cohort (N = 239) | Absolute bias, mL/min/1.73 m2, median (Q1–Q3) | −9.9 (−22.0 to 2.1) | −5.8 (−17.6 to 6.6) |
| Absolute bias, mL/min/1.73 m2, mean (95% CI) | −9.2 (−11.6 to −6.7) | −4.9 (−7.3 to −2.5) | |
| Precision, mL/min/1.73 m2 | 24.1 | 24.2 | |
| Relative bias, %, median (Q1–Q3) | −10.6 (−20.4 to 2.2) | −5.6 (−16.7 to 7.8) | |
| Relative bias, %, mean (95% CI) | −4.6 (−10.0 to 0.8) | −0.0 (−5.6 to 5.6) | |
| Accuracy, % (95% CI) | 79.9 (74.5–84.6) | 88.3 (83.8–91.9) | |
| Non-cancer, non-kidney donor cohort (N = 1136) | Absolute bias, mL/min/1.73 m2, median (Q1–Q3) | −4.3 (−17.1 to 6.8) | −1.2 (−13.8 to 10.5) |
| Absolute bias, mL/min/1.73 m2, mean (95% CI) | −4.8 (−6.1 to −3.5) | −1.4 (−2.7 to −0.1) | |
| Precision, mL/min/1.73 m2 | 23.9 | 24.3 | |
| Relative bias, %, median (Q1–Q3) | −7.0 (−22.1 to 11.9) | −1.7 (−17.9 to 18.0) | |
| Relative bias, %, mean (95% CI) | 1.3 (−1.4 to 3.9) | 6.7 (4.0–9.5) | |
| Accuracy, % (95% CI) | 63 (61–66) | 66 (63–69) |
CI, confidence interval.
Absolute bias is calculated as the difference between eGFR and mGFR; relative bias is calculated as the difference between eGFR and mGFR divided by the mGFR; precision is calculated as the IQR of the bias; and the accuracy is calculated as the percentage of patients with eGFR within the range of ±30% of the mGFR (P30).